Protective ground cover system

ABSTRACT

A protective ground cover system for reducing the impact of a fall onto a surface, said system including a first layer of loose fill material placed on or in the ground at an impact zone; at least one supporting layer, wherein each layer has open channels adapted to be filled by loose fill material and to enable fluid to pass there through, the at least one supporting layer positioned over the first layer; a second layer of loose fill material having a thickness less than the first layer and being placed on the at least one supporting layer, wherein the protective ground cover system substantially prevents displacement of the loose fill material away from the impact zone.

BACKGROUND OF THE INVENTION

The present invention relates to protective ground coverings and, moreparticularly, to a protective ground cover system for impact zones.

The protective ground cover under and around playground equipment(impact zones) is one of the most important factors in reducing thelikelihood of serious injuries from a fall. Such areas includeunderneath swings, monkey bars and slides, particularly at the base ofthe slide. Either unitary protective mats or loose fill can be used assupportive surfacing to provide such a safe environment for children.Critically, the support surfacing has to be at a particular depth andmaintained at that depth for a given critical height that a child mayaccidently fall from while playing on any playground equipment. However,maintaining such impact zone's ground cover can be challenging becauseplayground surfaces frequently become worn in a short period of timebecause of the high traffic and the nature of the activity. Over time,children's feet displace or kick out particulate or loose fill material,such as wood chips, originally set in place to provide additionalprotection for the child's fall. Similarly such high traffic andactivities tend to degrade unitary protective mats currently used inimpact zones.

Unitary protective mats are much more expensive than loose fill materialbecause of the material used and the effort required in the former'sconstruction and installation. Notably, the unitary mats, because of thenecessities of construction and installation, may be used to cover evennon-impact zones, further heightening their overall cost. The problemwith the less expensive loose fill material, as mentioned above, is thatit can quickly be displaced over time and so becomes costly to maintain(the required depth) and replace the loose fill material.

As can be seen, there is a need for a system that combines the low costof installing loose fill material while preventing its maintenancecosts.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a protective ground cover systemfor reducing the impact of a fall onto a surface defined by an impactzone, comprises: a first layer of loose fill material having apredetermined first thickness, wherein the first layer is placed on thesurface; at least one supporting layer, each supporting layercomprising: a substantially flat sheet having a plurality of openchannels, each channel having an upper opening at an upper surface ofthe sheet and a corresponding lower opening at a lower surface of thesheet, thereby enabling loose fill material to be retained therein andenabling fluid to flow there through, wherein the at least onesupporting layer lays over the first layer; and a second layer of loosefill material having a predetermined second thickness, wherein thesecond layer is placed on the at least one supporting layer, whereby theprotective ground cover system substantially prevents displacement ofthe loose fill material away from the impact zone.

In another aspect of the present invention, method of forming aprotective ground surface for reducing the impact of a fall onto asurface defined by an impact zone, comprises the steps of: forming afirst layer of loose fill material on or in the surface; placing atleast one supporting layer over the first layer, each supportingcomprising: a substantially flat sheet having a plurality of openchannels, each channel having an upper opening at an upper surface ofthe sheet and a corresponding lower opening at a lower surface of thesheet, thereby enabling loose fill material to be retained therein andenabling fluid to flow there through, wherein the at least onesupporting layer lays over the first layer; and forming a second layerof loose fill material of a predetermined thickness over the at leastone supporting layer, whereby the placement of the protective groundsurface substantially prevents displacement of the loose fill materialaway from the impact zone.

In yet another aspect of the present invention, a supporting layer forsubstantially preventing displacement of the loose fill material awayfrom a surface, comprises: a substantially flat sheet having a pluralityof open channel, each channel having an upper opening at an uppersurface of the sheet and a corresponding lower opening at a lowersurface of the sheet, thereby enabling loose fill material to beretained therein and enabling fluid to flow there through, and whereinthe spacing of the channels and the area of the upper openings thereofresult in the upper surface comprising a plurality of ridges extendingalong the support layer in at least two directions thereby forming agrid, whereby the plurality of ridges provide a non-skid surface forretaining loose fill material engaging the plurality of ridges.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdrawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary playground, illustratingthe impact zones where an exemplary embodiment of the present inventionmay be cost effectively utilized, as compared to providing a unitaryprotective mat to substantially cover the playground;

FIG. 2 is a plan view of an exemplary embodiment of the presentinvention;

FIG. 3 is a detailed perspective view of an exemplary embodiment of a atleast one supporting layer of the present invention;

FIG. 4 is a side view of an exemplary embodiment of the at least onesupporting layer of the present invention; and

FIG. 5 is a plan view of an exemplary embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is of the best currently contemplatedmodes of carrying out exemplary embodiments of the invention. Thedescription is not to be taken in a limiting sense, but is made merelyfor the purpose of illustrating the general principles of the invention,since the scope of the invention is best defined by the appended claims.

Broadly, an embodiment of the present invention provides a protectiveground cover system for reducing the impact of a fall onto a surface,said system including a first layer of loose fill material placed on orin the ground at an impact zone; at least one supporting layer, whereineach layer has open channels adapted to be filled by loose fill materialand to enable fluid to pass there through, the at least one supportinglayer positioned over the first layer; a second layer of loose fillmaterial having a thickness less than the first layer and being placedon the at least one supporting layer, wherein the protective groundcover system substantially prevents displacement of the loose fillmaterial away from the impact zone.

Referring to FIGS. 1 through 5, the present invention may includeprotective ground cover system 100 for impact zones. The ground coversystem 100 may include at least one supporting layer 15, a first layerof fill material 32 and a second layer of fill material 33.

Impact zones of a playground 11 may be disposed under and aroundplayground equipment, such as but not limited to a swing set 12, aclimbing frame 13 (monkey bars) and a slide 14, as illustrated inFIG. 1. Impact zones typically provide surfacing comprising loose fillmaterial, such as wood chips, wood mulch, wood fiber, sand, shreddedrubber mulch, pine bark and the like, over the top of a harder ground31. The loose fill material is designed to cushion any impact of achild's fall. However, impact zones not only circumscribe fallinghazards but may also be areas of heavy wear, such that particulatematerial is kicked out and dispersed. For example, underneath the swingsets 12, underneath the climbing frame 13 and underneath the slide 14particularly at the ladder end and at the bottom of the slide. In impactzones where the loose fill material may be kicked out, resulting in itsdiminished depth, the risk of serious injury to a fallen childincreases.

Each supporting layer 15 may be a substantially flat sheet providing aplurality of first channels 20 and smaller second channels 25 therethrough. Each channel 20, 25 may have an upper opening at the uppersurface of the at least one supporting layer 15 and a lower opening atthe lower surface of the at least one supporting layer 15. The upperopenings and lower openings can be substantially, oval, square, circularor other geometric shapes. Each upper opening has an area greater thanthe area of its complementary lower opening. The difference in arearestricts the flow of loose fill material through each first channel 20,25. Each channel 20, 25 may form a seat 21, 26 bounded by a sidewall 22,wherein the seat 21, 26 defines the lower opening and the sidewall 22defines the upper opening, both defining a hollow space or cavity 28there between. The cavities 28 are designed to house some of theparticulate material from the surface of the playground and prevent orsubstantially reduce the movement of the particulate material when ithas heavy use around playground equipment. The presence of the seat 21,26 bearing the weight of loose fill material in their complementarycavity 28 generally prevents the support layer 15 from moving,especially when the loose fill material about its upper layer may besignificantly diminished.

Arrangement of channels 20, 25 on a two-dimensional lattice patternsufficiently close together results in the upper surface of the at leastone supporting layer 15 comprising a plurality of elongated ridges 24formed within walls 23 separating adjoining channels 20, 25. Thetwo-dimensional lattice pattern results in these ridges 24 extendingalong the at least one supporting layer 15 in at least two directions toform a grid. The grid also provides a non-slip or non-skid surface forfoot traffic and/or as a means to retain loose fill material. Thearrangement of the fluid channels 20, 25 or ridges 24 may be altered inany suitable way so as to achieve desired non-skid, retention of otherfrictional properties for the upper surface of the at least onesupporting layer 15. Adjacent ridges 24 may define a small recess 29between their lengths. The channels 20, 25 may be arranged on the atleast one supporting layer 15 in any suitable way. The complementaryopenings in concert with the ridges 24 are adapted to substantiallyeliminate accumulation of fluid on the upper surface of the supportingsurface 15. Such alterations or adaptations shall fall within the scopeof the present disclosure or appended claims.

The at least one supporting layer 15 may be made from EPDM rubber, SBRrubber, other geo textile material, energy-absorbing material, or anycombination thereof. The at least one supporting layer 15 may be formedin any suitable way, including but not limited to molding, casting,stamping, extrusion, milling, 3D-printing or the like. In certainembodiments, the at least one supporting layer 15 may have a layerthickness of between about 20 mm/1″ and 30-mm/1¼″. The thickness can be300 mm/12″ or more if children are playing on something that is veryhigh. The impact absorbance for 200 mm is about 8″ so if the playequipment is 4.57 meters/15 feet or higher than the thickness needs tobe expanded to keep them safe. In other embodiments, the layer thicknessmay be any suitable thickness.

Referring to FIG. 4, the protective ground cover system 100 may bemounted in the ground 31 in a playground area 11 or any other area inwhich there is potential for a person to fall from a height onto theground. A series of metal rods or poles 34 are hooked onto a respectivecable tie 35 through a hook 36 near a corner of the at least onesupporting layer 15. Each of the rods 34 may be made of steel or othersuitable material, and can be any suitable length.

The first layer of fill material 32 may be formed by placing loose fillmaterial on a ground surface 30 defined by a trench or cavity 37 thatmay be dug out underneath the play equipment at the impact zone to apredetermined first thickness of between 100 mm (4″) and 200 mm (7″ ⅞″),preferably between 150 mm (6″) and 200 mm (7″ ⅞″) (shown as thickness Bin FIG. 4). The predetermined first thickness can be 300 mm/12″ or moreif children are playing on something that is very high. The impactabsorbance for 200 mm is about 8″ so if the play equipment is 4.57meters/15 feet or higher than the thickness needs to be expanded to keepthem safe. In an alternative embodiment, a trench is not dug out andinstead a layer of particulate material is formed of indefinitedimensions.

After the first layer of fill material 32 is formed the at least onesupporting layer 15 may be laid over the top of the first layer 32 witheach of the rods 34 driven into the ground 31. Sufficient length of eachrod 34 exists in the ground 31 (shown as depth C in FIG. 4) andsufficient length is located above the ground surface 30 (slightly lessthan B), adjusted to the actual thickness of B. The ends of the rods 34at which the hook 36 is located remains in a location underneath thebottom surface of the at least one supporting layer 15 for safetypurposes, whereby a child would not inadvertently be able to touch or beinjured by the hook 36 or the rod 34. Each of the cable ties 35 areloosely connected to a nearest channel 20, 25 to near each corner of theat least one supporting layer 15. The rods 34 may therefore keep the atleast one supporting layer 15 in its original position despite themovement and pressure applied by high usage areas in the vicinity of theplayground equipment.

Once the at least one supporting layer 15 is positioned in place, thesecond layer of fill material 33 may be formed by placing loose fillmaterial over the top of the at least one supporting layer 15 (shown asthickness A in FIG. 4). The second layer of fill material 33 put on topof the layer 15 may be either kicked off or knits into the openings 27and cavities 28 created by the channels 25, 20 and this binds the wholeloose fill material together and makes it difficult to move or displacethe fill material over time amid high usage. Usually a predeterminedsecond thickness of the second layer of fill material 33 is about 2″ asthe first layer of fill material 32 under the layer 15 in combinationwith the the layer 15 itself provides the most protection (impactabsorbance) of a fallen child. In an alternative embodiment, thepredetermined second thickness may be any suitable thickness.

A method of using the present invention may include the following. Aprotective ground cover system as disclosed above may be provided. Auser may initially dig out a small pit 37, as mentioned previously to adepth of 100 mm (4″) to 200 mm (7″ ⅞″) preferably between 150 mm (6″) to200 mm (7″ ⅞″) in the desired impact zone around the playgroundequipment. The rods 34 are then secured near each corner of the at leastone supporting layer 15 to the cable ties 35 and the first layer of fillmaterial 32 may be added into the trench 37. The at least one supportinglayer 15 may then be placed over the layer 32 and the rods 34 are driveninto the ground 31 to sufficient depths. In certain embodiments thesufficient depth may be of 4″ to 6″. The second layer of fill material33 may then be placed over the top of the at least one supporting layer15.

FIG. 5 shows two at least one supporting layers 15 that can be joinedtogether by cable ties 35, along adjacent sides, through convenientchannels 20 or 25 on adjoining at least one supporting layers 15. Aplurality of at least one supporting layers 15 may be required to betied together in situations, for example, underneath the climbing frame13 shown in FIG. 1 or underneath swings 12. The plurality of at leastone supporting layers 15 may be laid on a generally shared surface in aside-by-side arrangement. As many cable ties 35 as are needed can beused to joint two or more at least one supporting layer 15 together.Typically two to three cable ties are used along the sides of adjoiningat least one supporting layer 15.

The supportive ground cover system 100 was tested by TÜV SÜD America andmeets the requirements of U.S. Consumer Product Safety Commissionstandards ASTM F1292-09. According to TÜV SÜD America the test samplesexceeded the maximum capabilities of the test equipment and met therequirements specified in ASTM F1292-09 for a 15 foot impact height.

The system 100 has been tested with a depth of 200 mm/8″, with the firstlayer 32 of 150 mm/6″ of loose fill pine chip material, a rubber atleast one supporting layer 15 and the second layer 33 of 50 mm of loosefill pine chip material, the critical fall height (for example from ontop of monkey bars or a climbing frame 13) was 3.1 meters. The samecritical fall height was achieved without the use of the supportingsurface 15, that is, just with a 200 mm/8″ layer of loose fill pine orwood chip material. This shows that the softfall properties of the loosefill material are maintained with the presence of the at least onesupporting layer 15, as the at least one supporting layer 15 retains theparticulate material in place such that it is lessens the effect ofdispersion of the material (particularly in the first layer 32) awayfrom heavy foot traffic areas, and allows recovery of some surfacematerial displacement caused by various impacts due to the elasticrecovery response of the at least one supporting layer 15. If for somereason the second layer 33 is moved over time, the at least onesupporting layer 15 retains the first layer 32 of particulate materialin place to meet the softfall and surfacing requirements. It is alsofound that the recommended installation depth for the loose fillmaterial is reduced with the addition of the retention at least onesupporting layer 15.

It should be understood, of course, that the foregoing relates toexemplary embodiments of the invention and that modifications may bemade without departing from the spirit and scope of the invention as setforth in the following claims.

What is claimed is:
 1. A protective ground cover system for reducing theimpact of a fall onto a surface defined by an impact zone, comprising: afirst layer of loose fill material having a predetermined firstthickness, wherein the first layer is placed on the surface; at leastone supporting layer, each supporting layer comprising: a substantiallyflat sheet having a plurality of open channels, each channel having anupper opening at an upper surface of the sheet and a corresponding loweropening at a lower surface of the sheet, thereby enabling loose fillmaterial to be retained therein and enabling fluid to flow therethrough, wherein the at least one supporting layer lays over the firstlayer; and a second layer of loose fill material having a predeterminedsecond thickness, wherein the second layer is placed on the at least onesupporting layer, whereby the protective ground cover systemsubstantially prevents displacement of the loose fill material away fromthe impact zone.
 2. The system of claim 1, wherein the predeterminedsecond thickness has a thickness less than the predetermined firstthickness.
 3. The system of claim 2, wherein the predetermined firstthickness is between about 100 mm and about 200 mm.
 4. The system ofclaim 2, wherein the predetermined second thickness is at least 40 mm.5. The system of claim 1, wherein the spacing of the channels and thearea of the upper openings thereof result in the upper surfacecomprising a plurality of ridges extending along each support layer inat least two directions thereby forming a grid.
 6. The system of claim5, wherein the plurality of ridges provide a non-skid surface.
 7. Thesystem of claim 1, further providing a secure attachment between the atleast one supporting layer and the impact zone surface.
 8. The system ofclaim 7, wherein the secure attachment includes a plurality of rods,wherein each rod is secured at a first end to a portion of supportinglayer and secured at a second end to the surface.
 9. The system of claim7, wherein the second end is driven into the surface a depth rangingfrom about four to about six inches.
 10. The system of claim 7, whereineach rod has a hook at the first end and is positioned below the atleast one supporting layer within the first layer of loose fillmaterial.
 11. The system of claim 5, wherein the at least one supportinglayer has a layer thickness of between about 20 mm and 30 mm.
 12. Amethod of forming a protective ground surface for reducing the impact ofa fall onto a surface defined by an impact zone, comprising the stepsof: forming a first layer of loose fill material on or in the surface;placing at least one supporting layer over the first layer, eachsupporting comprising: a substantially flat sheet having a plurality ofopen channels, each channel having an upper opening at an upper surfaceof the sheet and a corresponding lower opening at a lower surface of thesheet, thereby enabling loose fill material to be retained therein andenabling fluid to flow there through, wherein the at least onesupporting layer lays over the first layer; and forming a second layerof loose fill material of a predetermined thickness over the at leastone supporting layer, whereby the placement of the protective groundsurface substantially prevents displacement of the loose fill materialaway from the impact zone.
 13. The method of claim 12, wherein thepredetermined second thickness has a thickness less than thepredetermined first thickness.
 14. The method of claim 13, wherein thepredetermined first thickness is between about 100 mm and about 200 mm.15. The method of claim 13, wherein the predetermined second thicknessis at least 40 mm.
 16. The method of claim 12, wherein the spacing ofthe channels and the area of the upper openings thereof result in theupper surface comprising a plurality of ridges extending along eachsupport layer in at least two directions thereby forming a grid.
 17. Themethod of claim 16, further including forming a secured attachmentbetween the at least one supporting layer and the impact zone surface.18. The method of claim 17, wherein the secured attachment includes aplurality of rods, wherein each rod is secured at a first end to aportion of each of the at least one supporting layer and secured at asecond end to the surface.
 19. The method of claim 18, wherein each rodhas a hook at the first end and is positioned below the at least onesupporting layer within the first layer of loose fill material.
 20. Asupporting layer for substantially preventing displacement of the loosefill material away from a surface, comprising: a substantially flatsheet having a plurality of open channel, each channel having an upperopening at an upper surface of the sheet and a corresponding loweropening at a lower surface of the sheet, thereby enabling loose fillmaterial to be retained therein and enabling fluid to flow therethrough, and wherein the spacing of the channels and the area of theupper openings thereof result in the upper surface comprising aplurality of ridges extending along the support layer in at least twodirections thereby forming a grid, whereby the plurality of ridgesprovide a non-skid surface for retaining loose fill material engagingthe plurality of ridges.